42.5% is the change from 320 to 456
Calculation steps:
[( 456 - 320 ) ÷ 320] x 100 = 42.5%
Formula
Percentage change = [(456 - 320) / 320] x 100
Subtract the new number by the original number
456 - 320 = 136
136 ÷ 320 = 0.425
0.425 x 100 = 42.5%
Example